What is the importance of family in nation stability ?

A nation exists only in the imaginations of its citizens. A nation appoints leaders because its citizens wish it to be so not because they actually need leaders. If the leaders seem to be corrupt, it is because they correctly represent a corrupt electorate. If it is not so, the people will refuse to support the regime and the regime will collapse. They don't have to throw it down, just stop holding it up.

Asking how this relates to families is like asking how houses relate to the materials used to build them. For instance, nations are protected by an internal army, usually called state police or some similar term. Police are citizens, so if the citizens rebel against their state, then there is a battle between citizens and citizens. The battle turns at the moment when the police realize that they have to switch sides to protect their families.